Morphological variation of Chrysanthemum lavandulifolium induced by 5-azaC treatment

Abstract

Abstract To explore the possible role of DNA methylation in plant development. Different concentrations of the DNA methyltransferase inhibitor 5-azacytidine were used on different components of Chrysanthemum lavandulifolium (stem and hypocotyl). The effects of 5-azaC on plantlet growth and flower development were investigated. Results showed that low concentrations of 5-azaC (20\u202fμmol L−1–100\u202fμmol L−1) inhibited plantlet growth (from the stem segments), and high concentrations of 5-azaC (150\u202fμmol L−1–200\u202fμmol L−1) promoted plantlet growth. This inhibition is similar in the regeneration of hypocotyls, except that the concentration range of 5-azaC is different. Low concentration of 5-azaC (10\u202fμmol L−1–20\u202fμmol L−1) inhibit generation or growth of callus-generated plantlets, high concentration of 5-azaC (150\u202fμmol L−1–200\u202fμmol L−1) promoted the growth of hypocotyl regeneration seedlings. In thus, the inhibitory effect of plantlet was similar in hypocotyl regeneration. Therefore, different explants have different sensitivities to methyltransferase inhibitor (5-azaC) treatment. Progeny plants treated with stems of C. lavandulifolium under the short days condition, the control plants (about 15 leaves) did not bloom, plants undergoing high concentration treatments flowered in some strains (flowering rate 80% in treatment 6), and the pitch of all unflowering plants was dwarfed. It seems that 5-azaC can break the C. lavandulifolium adolescent period limit, potentially by inducing the photoperiodic in advance or through another mechanism, after 5-azaC processing may alters key gene methylation, resulting in flowering. In the hypocotyl-treated progeny after multiple passages, all treatments had flowering and non-flowering lines under short-day conditions, and the flowering rate was between 39.29% and 78.43%. We also obtained a continuous flowering line was obtained (2-8-2), and this trait exhibited stable by asexual reproduction. In addition, abundant variation in leaf morphology, flower shape and stem color variation were observed in hypocotyl regeneration plants. All the evidence suggests that the methyltransferase inhibitor (5-azaC) may affect the DNA methylation level of many key genes regulating plant growth and development. This study provides phenotypic data and materials for further exploring the role of DNA methylation in the growth and flower induction of C. lavandulifolium.